Extremely small, rugged, shunted Micro-Jax® 2-conductor jack is 1/4 the size of a standard phone jack and weighs less than 1/20 ounce. Can be wired for open or closed circuit operation. Internally keyed insulators interlock all parts and tip springs grip mating plugs positively. Mates with Switchcraft Micro-Plug® phone plugs. Jacks mount through .190" diameter hole in chassis/panels up to .093" thick. For insulated mounting, a .281" diameter hole and .050" maximum panel thickness applies.